权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development and Characterization of Novel Refractory High-Entropy Alloys for High Temperature Applications

高温应用新型难熔高熵合金的开发和表征

基本信息

批准号：
262854559
负责人：
Professorin Dr.-Ing. Bronislava Gorr
金额：
--
依托单位：
Institut für Angewandte Materialien - Werkstoffkunde (IAM-WK)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/262854559?language=en
关键词：
Development Characterization Novel Refractory Entropy

项目摘要

Nowadays, Ni-based superalloys are the dominant material class for high temperature applications. However, their use is strictly limited by their melting point of around 1400°C. In this project, so called High Entropy Alloys (HEA), which are based on refractory metals, will be proposed as novel high temperature structural materials. The appealing difference of the concept of HEA is that all alloy elements exhibit equimolar or near-equimolar concentrations. Thus, from a simplified thermodynamic point of view, the formation of random solid solutions being potentially ductile phases is favored against intermetallic compounds, which are often complex and brittle in nature. As a further consequence, this simple microstructure may yield an attractive property profile such as high thermal stability and high temperature strength while being tough and even ductile at ambient temperatures.First results clearly show that the alloy 20Mo-20W-20Al-20Cr-20Ti possesses a single phase microstructure, which is body centered cubic. Although many materials containing refractory metals suffer from severe oxidation, the alloy studied reveals a surprisingly good high temperature oxidation resistance. Besides, the calculated melting point is approximately 300°C higher than that of commercial Ni-based superalloys. In this proposal, new HEA based on the system Mo-W-Al-X-Y will be developed. Three reference alloys with the following chemical compositions are chosen for further investigations: (i) 20Mo-20W-20Al-20Cr-20Ti, (ii) 20Mo-20W-20Al-20Cr-20Mn und (iii) 20Mo-20W-20Al-20Mn-20Ti. Since the HEA approach allows micro-alloying, the effect of several additional elements, such as B, Zr, Si, and Y will be studied. Well known from past experience with conventional alloys, the addition of B and Zr may lead to a significant improvement of mechanical properties, whereas alloying with Si and Y may cause a substantial increase of the oxidation protectiveness. This proposal mainly aims at the exploration of potential of novel refractory HEA and the development of physical metallurgy strategies to satisfy the requirements for high temperature applications. Experimental investigations will be focused on extensive microstructural analysis, creep behavior, and high temperature oxidation resistance. Based on this, metallurgical approaches on targeted alloy development can be derived which may facilitate property improvement with respect to future high temperature applications.

如今，镍基高温合金是高温应用的主要材料类别。然而，它们的使用受到其约1400°C的熔点的严格限制。在这个项目中，所谓的高熵合金（HEA），这是基于难熔金属，将被提出作为新的高温结构材料。HEA概念的吸引人的区别在于所有合金元素都表现出等摩尔或接近等摩尔的浓度。因此，从简化的热力学观点来看，作为潜在延展相的无规固溶体的形成相对于金属间化合物是有利的，金属间化合物通常是复杂的且本质上是脆性的。结果表明，20 Mo-20 W-20 Al-20 Cr-20 Ti合金具有体心立方结构的单相显微组织。虽然许多含有难熔金属的材料会遭受严重的氧化，但所研究的合金显示出令人惊讶的良好的高温抗氧化性。此外，计算的熔点比商业镍基高温合金高约300°C。在该提案中，将开发基于Mo-W-Al-X-Y系统的新HEA。选择具有以下化学成分的三种参考合金用于进一步研究：（i）20 Mo-20 W-20 Al-20 Cr-20 Ti，（ii）20 Mo-20 W-20 Al-20 Cr-20 Mn和（iii）20 Mo-20 W-20 Al-20 Mn-20 Ti。由于HEA方法允许微合金化，因此将研究几种附加元素如B、Zr、Si和Y的影响。从以往的常规合金经验中可知，添加B和Zr可导致机械性能的显著改善，而与Si和Y合金化可导致氧化保护性的显著增加。本项目主要是探索新型耐火材料HEA的潜力，并开发满足高温应用要求的物理冶金策略。实验研究将集中在广泛的微观结构分析，蠕变行为和高温抗氧化性。在此基础上，冶金方法对目标合金的发展，可以得出，这可能有助于改善性能，相对于未来的高温应用。